The equation is y = 20(1.40)^x
where x is the number of days and y is the future amount after x days go by
The 1.40 is from the fact that 1+r = 1+0.40 = 1.40, where r is the decimal form of 40%, so r = 0.40
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Plug in x = 7 to get
y = 20(1.40)^x
y = 20(1.40)^7
y = 210.827008
y = 211
We round to the nearest whole number since it doesn't make much sense to have a fractional portion of an algae. After 7 days, there are about <u>211</u> algae.
Answer:
7/54 or 0.1296
Step-by-step explanation:
So here you're using system of equations. You can solve systems by graphing, elimination, or substitution. Ill use substitution. First lets solve for x. take the second equation and add y to both sides to get x by itself:
x - y = 75
x = y + 75 now plug y+75 in for x in the first equation
x + y = 743
(y +75) +y = 743 solve for y
2y +75 = 743 subtract 75
2y = 668 divide both sides by 2
y = 334
now plug this into any of the 2 equations to solve for x i chose the second one
x - y = 75
x - 334 = 75 add 334 to both sides
x = 409
This means x, sold before the tournament is 409 and y, sold at the door is 334. That means the assistant is wrong and accidentally flipped the two answers
